Introduction

DNA denaturation involves the separation of the two complementary strands of the double helix. This process requires disruption of the hydrogen bonds between base pairs and destabilization of base stacking interactions. Various physical and chemical agents can induce DNA denaturation.

Common DNA Denaturing Agents

• Heat: Raises temperature to disrupt hydrogen bonds.

• Alkaline solutions (e.g., NaOH): Change pH to break hydrogen bonding.

• Organic solvents (e.g., formamide, DMSO): Interfere with hydrogen bonds and base stacking.

• Chaotropic agents: Disrupt water structure and weaken hydrophobic interactions.

Role of Formamide in DNA Denaturation

• Formamide is a small, polar organic molecule that lowers the melting temperature (Tm) of DNA by disrupting hydrogen bonds between base pairs.

• It stabilizes the single-stranded form by interacting with bases, preventing reannealing.

• Formamide is widely used in molecular biology protocols to denature DNA at lower temperatures, protecting DNA integrity.

Analysis of Options

Conclusion

Among the given options, formamide is the chemical agent that effectively denatures double-stranded DNA by disrupting hydrogen bonding and lowering the melting temperature.

Keywords

DNA denaturation, formamide, hydrogen bond disruption, DNA melting, chemical denaturants, DNA stability, molecular biology, DNA hybridization, organic solvents, DNA melting temperature

Correct answer:
(1) Formamide